Can aeration to fight algae hurt fish?

[mcmhc610]

Last summer, we bought a house that came with an approximately 1acre pond that's 2-4'deep and has about 7-10 large koi (3-4' in length). The pond was covered with algae all summer and wasn't very attractive. We bought an aeration system with 4 different air lines. Before we install it, we want to know if too much air can be harmful to the fish. They are beautiful and have obviously been living quite happily in this pond for a long time. If it is harmful, how would we know what the right amount of oxygen is to keep the algae down and the fish happy? Thanks for your help.

 

[Mmathis]

Hello and welcome! Would love to see pictures!

In general, air is always good for ponds and fish.

 

[Jhn]

Agree with Mmathis, an aerator will do nothing but help with oxygenation of the pond(ie you can’t really put too much oxygen in the water). It will also keep open areas at the waters Surface for Gas exchange, which the algae when coating the entire pond can inhibit it.
An aerator may help some with the reducing the algae, but won’t solve it, usually plants and lots of them are the key to starving out algae, and making sure run off can’t get into the pond. The idea is to cut off what you can somewhat control that gets algae to grow which is excess nutrients.

Sounds like you have the potential for a nice pond. Are there other fish in the pond as well like game fish, etc...

 

[j.w]

@mcmhc610
Aeration is good. I have a bubbling volcano in my 2400 gal pond and fish love zooming through it playing in the bubbles! There are calmer areas for them to go to if they choose. Plants suck up the extra nutrients that the algae likes to use to grow. Sedge plants are good suckers. Iris are too but you have to keep them under control or they will take over.

 

[mcmhc610]

Hello and welcome! Would love to see pictures!

In general, air is always good for ponds and fish.

Agree with Mmathis, an aerator will do nothing but help with oxygenation of the pond(ie you can’t really put too much oxygen in the water). It will also keep open areas at the waters Surface for Gas exchange, which the algae when coating the entire pond can inhibit it.
An aerator may help some with the reducing the algae, but won’t solve it, usually plants and lots of them are the key to starving out algae, and making sure run off can’t get into the pond. The idea is to cut off what you can somewhat control that gets algae to grow which is excess nutrients.

Sounds like you have the potential for a nice pond. Are there other fish in the pond as well like game fish, etc...

There are a few sunnies. We added some trout, but that was a waste of $$ as the blue heron ate them all.

The pond is spring-fed via an underground pipe and there's a waterfall going out of the pond. So, really, instead of the pump, we need more plants? I will research, but is there anything you could recommend? We live in NJ, so it's cold in winter.

 

[poconojoe]

Plants and lots of them will compete with the algae by feeding on the excess nutrients.

If your pond is exposed to a lot of sun, that can enhance the problem. There are floating plants that can help shade the water. If your pond was smaller, you could hang a sun shade, but your pond is huge.

 

[mcmhc610]

This is my favorite pic of the pond. This was in December 2020, a week before our first snow storm. Will post more pics as spring blooms.

 

[addy1]

Beautiful!

 

[Lisak1]

While aeration is never "bad" for fish, some fish do prefer stiller waters. In a smaller pond, you could potentially stress fish that like still water with too much movement, but in your beautiful pond I think you can provide both aeration and plenty of areas for those native fish that may prefer to just hang out and chill.

 

[Mike in Vermont]

There are a few sunnies. We added some trout, but that was a waste of $$ as the blue heron ate them all.

The pond is spring-fed via an underground pipe and there's a waterfall going out of the pond. So, really, instead of the pump, we need more plants? I will research, but is there anything you could recommend? We live in NJ, so it's cold in winter.

If you intend to add more trout, I can tell you that too much aeration is not good for them. The reason is, it will pull the cool water up to the surface, and the trout won't have a cool place to go. They start feeling stress at a water temp of 70 degrees, and die when it reaches 80. am surprised the Heron were able to catch the trout, unless they were stressed from warm water. If that happens, they will start swimming around the edges of the pond, and become vulnerable to Heron and other predators.

 

[MamaOwl]

Woah! That's a lake!